compiling gcc under Ultrix

[Kenneth J. Heeres]

I am attempting to install gcc on a decstation 5000 under
ultrix 4.1.  I use config.gcc with the decstation option.
I received the following error during make:
  stddef.h line 12  illegal type combination
   typedef unsigned long size_t;

I tried compiling this statement in a separate file and did
not receive the error.  I assume I am having a problem with
a previous definition.  Does anyone know what is going on?

thanks,

ken